The RGD (Arg-Gly-Asp) is a potential cell-binding motif of UNC-52/PERLECAN.

UNC-52/perlecan is a basement membrane (BM) proteoglycan playing an essential role in the muscle cell attachment of C. elegans. The UNC-52 protein contains two RGD (Arg-Gly-Asp) motifs in domains III and IV, a well-characterized tripeptide known for binding to mammalian β integrin. To investigate the role of the RGD motif in UNC-52/perlecan, we created two mutations in the ²⁰²¹ RGD ²⁰²³ motif: one mutation changed the RGD to an RGE, and the other deleted the RGD motif. The RGE ²⁰²³ caused defective actin filaments and aberrant localization of PAT-3 β integrin and TLN-1/talin. Additionally, the in-frame deletion of RGD ²⁰²³ resulted in a paralyzed and arrested at two-fold embryonic stages (Pat) phenotype, which is the identical phenotype of the pat-3 β integrin null allele. These results indicate that RGD ²⁰²³ is a potential ligand for cell binding and is essential for development and survival. Furthermore, our analysis reveals that the RGD of an invertebrate BM molecule is a potential cell-binding motif, suggesting that the function of the RGD motif is conserved among species.
Competing Interests: Declaration of competing interest Authors declare no conflict of interest to the project described in the manuscript above.
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